DNA MIDTERMS - THE STRUCTURE OF PROKARYOTIC AND EUKARYOTIC CELLS

components of cell

1. cell membrane

2. cytoplasm

3. nucleus

components of the nucleus

1. nuclear envelope

2. chromatin

3. nucleolus

this have flagella for movement

prokaryotic

short and circular

prokaryotic DNA

longer and contained in chromosome

eukaryotic DNA

Instructions (piece of DNA sequence) to manufacture proteins (determine inherited traits)

the gene

gene expression can be:"

turned on (enhanced) or turned off (repressed)

Most of the life of the cell around 90%

chromatin

Coiled DNA strands to basic proteins called histone

chromatin

Present in metabolically active cells

chromatin

Chromatin that has undergone further condensation

chromosome

from thinly coiled material, nag condense siya into packed material

condensation of chromatin to chromosome

Present in actively dividing cells (or mitosis)

chromosome

you cannot see this under the microscope

chromatin

tightly packed DNA

chromosome

this is found during cell division (mitosis)

chromosome

found throughout the interphase

chromatin

2 types of chromatin

1. Heterochromatin

2. Euchromatin

not functional chromatin

heterochromatin

dense type of chromatin under light microscope and is tightly coiled around histone (not used by the cell)

heterochromatin

types of heterochromatin

a. marginal chromatin

b. karyosome

c. nucleolar-associate chromatin

densely packed chromatin

heterochromatin

sex chromosome

XX and XY

remains tightly coiled and visible while the other one is uncoil

female (XX)

this is found in females

barr body

walang one that is coiled and visible. x chromosome is always uncoiled

males (XY)

darkly stained

euchromatin

lightly stained

heterochromatin

these are no sex cells

somatic cells

cells in our body that is not from sperm or egg

somatic cells

how many pairs - somatic ells

23 pairs

is somatic cell a haploid or diploid?

diploid

complete set of chromosomes of the person

karyotype

is germ cell haploid? or diploid?

diploid

there is only 1 (X), so the total number of chromosome is reduced (instead of 46, XX - 45 X nalang)

Turner Syndrome (Females):

characteristics is man like even if she is genetically female (poor breast development, broad shoulders, undeveloped ovaries (no menstrations)

Turner Syndrome (Females):

47 XXY - instead of 1 pair of sex chromosome lang (XY), naging tatlo ang sex chromosome (XXY)

Klinefelter Syndrome (Males)

short arm

P

long arm

Q

what is the fertilized egg

zygote

classification of chromosome

1. homologous chromosome

2. homomorphic chromosome (autosomes)

3. heteromorphic chromosome (sex chromosome)

chromosome that is paired because they encode the same traits

homologous chromosome

First 22 pairs made of identical partners (autosomes)

homomorphic chromosome

chromosome that is not the same morphology

heteromorphic chromosome

Chromosome consist of 2 parallel strands

chromatids

chromatids is joined together by

centromere

Portion of the centromere where the mitotic spindle will attach to

kinetochore

this will pull the chromosome

mitotic spindle

morphological types of chromosome

1. metacentric

2. submetacentric

3. acrocentric

4. telocentric

centromere is in the middle

metacentric

between the midpoint and one end

submetacentric

near one end

acrocentric

at the end (no short arm and no chromo)

telocentric

Protects the chromosome during cell division from deterioration

telomere

where all the preparation are done before the cell divides

interphase

90% of the life of the cell

interphase

3 stages of interphase

• G1

• S

• G2

biosynthetic activities of the cell like metabolism (25%)

G2

Starts when DNA replication commences (40%)

S

Accumulation of energy for mitosis (25%)

G2

Results in 2 Daughter cells possessing identical copies of the genome of the parent cell

mitosis

occurs in somatic cells except gametes

mitosis

10% of the life of the cell

mitosis

mitosis phases

1. prophase

2. metaphase

3. anaphase

4. telophase

mitosis phase

• where you can see the mitotic spindle formation

• chromosome continues to condense

prophase

mitosis phase

• Alignment of chromosomes in the same plane in the middle of the cell to form the equatorial plate (metaphase plate)

• single file arrangement

metaphase

mitosis phase

• Separation of the single kinetochore of each pair of chromatids into two

• Sister chromatids are free to move to opposite poles of the spindle

anaphase

mitosis phase

• There will be another ‘nuclear membrane formation’ in each of the poles

• Chromosomes unfold back into Chromatin

• Nuclear reappear

• Cell continues to Elongate

telophase

it is the sign that the cells are about to divide into 2

Cleave Furrow Formation

Physical process of cell division. The cell is moving into one part to two parts

cytokinesis